1. Field of the Invention
The present invention relates generally to tools designed to remove broken pieces of other tools, and more particularly, to a new tool especially adapted to remove broken taps from materials in which the taps break.
2. Description of the Prior Art
Tools designed to remove or extract a broken piece of another tool are well known in the art. For example, the following U.S. patents are known: U.S. Pat. Nos. 4,078,458 of Berendzen; 4,389,913 of Drouin et al; 4,688,315 of Jannke; and 4,831,902 of McClure. More specifically, the Berendzen, Drouin et al, Jannke, and McClure patents disclose devices designed to remove broken screws from materials in which the screws break. All of these devices require a cutting operation to enable the extraction tool to extract the broken screw. None of the these tools are designed to remove a broken tap from material in which the tap breaks. Moreover, none of these prior art tools are designed to remove the broken other tool without a cutting operation.
More specifically, a tap is designed to cut threads into a material. An exemplary tap is shown in U.S. Pat. No. 4,271,554 of Grenell. A tap has at least two oppositely positioned cutting elements. A tap also has portions which support the cutting elements but which do not effect any cutting themselves. When the tap is rotated in a hole, the rotating cutting elements create a cylindrically tapped hole, and a space is left, adjacent to the non-cutting tap portions, for cut material to deposit. Sometimes, an excessive amount of torque is applied to the tap, and the tap breaks. Removing the broken tap is a difficult problem.
Thus, while the foregoing body of prior art indicates it to be well known to use extraction tools to extract broken screws from a material using a cutting operation, the provision of a simple and cost effective device is not contemplated to remove a broken tap from the material in which the tap breaks. Also, the prior art does not provide first extraction tools that are designed to remove a broken second tool without a cutting operation. The foregoing disadvantages are overcome by the unique broken tap extraction apparatus of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.